Theranos Inc., the blood-testing company accused of perpetrating Silicon Valley’s biggest fraud, will soon cease to exist. In the wake of a high-profile scandal, the company will formally dissolve, according to a shareholder email. Theranos will seek to pay unsecured creditors its remaining cash in coming months, the letter said. The move comes after federal prosecutors filed criminal charges against Theranos founder Elizabeth Holmes and the blood-testing company’s former No. 2 executive, alleging that they defrauded investors out of hundreds of millions of dollars and defrauded doctors and patients.